102 
MANUFACTURE  OF  CASTOE  OIL. 
ern  rail  roads  for  oiling  the  axles  of  cars,  and  probably  also  on 
the  locomotives.  Since  the  rise  in  the  price  of  whale  oil,  the 
attention  of  machinists  has  been  turned  to  various  substitutes, 
and  it  is  probable  that  the  non-drying  quality  of  castor  oil, 
when  pure,  will  render  it  very  valuable  for  lubricating  purposes, 
if  it  can  be  produced  at  a  sufficiently  low  price. 
The  chemistry  of  castor  oil  is  exceedingly  interesting  since 
the  researches  of  M.  Bouis  (Am.  Jour.  Pharm.  vol.  xxvi,  414,)  and 
others,  proving  it  to  be  capable  of  yielding  a  fourth  of  its  weight 
of  sebacic  acid  by  distillation  with  potash,  which  it  has  been 
suggested  may  be  applied  to  illuminating  purposes  like  sperma- 
ceti and  stearic  acid.  The  variableness  of  castor  oil  in  quality, 
as  regards  color,  odor,  and  taste,  may  easily  be  accounted  for  by 
reference  to  the  preceding  statements  of  the  mode  of  manufac- 
ture. The  object  of  kiln-drying  the  beans,  is  to  free  them  from 
moisture,  and  by  thus  toughening  the  albuminous  tissues,  to  ren- 
der them  less  liable  to  pass  out  in  an  emulsive  form,  with  the  oil. 
It  may  be,  also,  that  this  heating,  when  it  immediately  precedes 
the  expression,  greatly  facilitates  the  flow  of  the  oil  by  increasing 
its  liquidity. 
Pure  castor  oil,  according  to  Lowig,  consists,  proximately,  of 
ricinin  and  palmitin,  two  neutral  fatty  substances.  The  last  is 
bland,  and  is  identical  with  one  of  the  fats  in  palm  oil ;  whilst 
the  ricinin  is  less  bland,  and  by  saponification,  or  by  excessive 
heat,  yields  ricinic  acid,  an  exceedingly  acrid  substance,  which 
is  the  chief  cause  of  the  increased  activity  of  old  rancid  castor 
oil.  Now  it  is  not  improbable,  that  occasionally  the  excessive 
application  of  heat  may  partially  act  on  this  ingredient  of  the 
oil,  either  in  the  preliminary  process  of  drying,  or  in  the  subse- 
quent steps  of  boiling  the  oil  with  a  little  water  till  the  moisture 
is  driven  off.  Another  cause  of  inferiority  in  oil,  may  be  the 
occasional  use  of  old  beans.  There  is  much  yet  to  be  learned 
in  reference  to  the  proximate  chemistry  of  castor  oil  beans.  Mr. 
Henry  A.  Bower,  (Amer.  Jour.  Pharm.,  vol.  xxvi,  page  207)  has 
shown  that  the  albumen  of  the  seeds  are  analogous  to,  if  not 
identical  with,  the  emulsin  of  almonds ; — also  that  the  peculiar 
nauseous  odor  which  is  developed  when  the  seeds  are  triturated 
with  water,  is  probably  due  to  a  substance  that  does  not  pre-exist 
